Unify params and values, introduce helpers to deal with fields.

params.go

@@ -0,0 +1,100 @@
+package tgbotapi
+
+import (
+	"encoding/json"
+	"reflect"
+	"strconv"
+)
+
+// Params represents a set of parameters that gets passed to a request.
+type Params map[string]string
+
+// AddNonEmpty adds a value if it not an empty string.
+func (p Params) AddNonEmpty(key, value string) {
+	if value != "" {
+		p[key] = value
+	}
+}
+
+// AddNonZero adds a value if it is not zero.
+func (p Params) AddNonZero(key string, value int) {
+	if value != 0 {
+		p[key] = strconv.Itoa(value)
+	}
+}
+
+// AddNonZero64 is the same as AddNonZero except uses an int64.
+func (p Params) AddNonZero64(key string, value int64) {
+	if value != 0 {
+		p[key] = strconv.FormatInt(value, 10)
+	}
+}
+
+// AddBool adds a value of a bool if it is true.
+func (p Params) AddBool(key string, value bool) {
+	if value {
+		p[key] = strconv.FormatBool(value)
+	}
+}
+
+// AddNonNilBool adds the value of a bool pointer if not nil.
+func (p Params) AddNonNilBool(key string, value *bool) {
+	if value != nil {
+		p[key] = strconv.FormatBool(*value)
+	}
+}
+
+// AddNonZeroFloat adds a floating point value that is not zero.
+func (p Params) AddNonZeroFloat(key string, value float64) {
+	if value != 0 {
+		p[key] = strconv.FormatFloat(value, 'f', 6, 64)
+	}
+}
+
+// AddInterface adds an interface if it is not nill and can be JSON marshalled.
+func (p Params) AddInterface(key string, value interface{}) error {
+	if value == nil || (reflect.ValueOf(value).Kind() == reflect.Ptr && reflect.ValueOf(value).IsNil()) {
+		return nil
+	}
+
+	b, err := json.Marshal(value)
+	if err != nil {
+		return err
+	}
+
+	p[key] = string(b)
+
+	return nil
+}
+
+// AddFirstValid attempts to add the first item that is not a default value.
+//
+// For example, AddFirstValid(0, "", "test") would add "test".
+func (p Params) AddFirstValid(key string, args ...interface{}) error {
+	for _, arg := range args {
+		switch v := arg.(type) {
+		case int:
+			if v != 0 {
+				p[key] = strconv.Itoa(v)
+			}
+		case int64:
+			if v != 0 {
+				p[key] = strconv.FormatInt(v, 10)
+			}
+		case string:
+			if v != "" {
+				p[key] = v
+			}
+		case nil:
+		default:
+			b, err := json.Marshal(arg)
+			if err != nil {
+				return err
+			}
+
+			p[key] = string(b)
+		}
+	}
+
+	return nil
+}